1. Field of the Invention
The invention relates in general to simulation systems for providing stimuli to a mobile user with a head-mounted display, and in particular to a novel system for transmitting data to a user, receiving control inputs from the user, and transmitting user position and/or orientation information in a wireless manner.
2. Related Art
Various simulation systems are known for providing a simulated environment, in the form of audio and visual cues, to a user in applications such as training, system or building design, entertainment, and other applications that allow users to explore the simulated three-dimensional aspects of entities or environments. Such systems typically include a processor for generating data describing the virtual environment, means for converting the data into electrical signals containing audio and video information, a head-mounted display for providing visual cues in accordance with such signals, speakers or headphones for providing audio cues in accordance with such signals, and user-input devices for providing feedback which is used by the processor to update the data which it generates.
U.S. Pat. No. 5,671,158 to Fournier et al. discloses an apparatus and method for wireless and interactive communication between a computer and a technician. The computer is equipped with video and audio transmitters, and an audio receiver. The technician wears a portable user interface, including a communication pack with a video receiver, audio receiver, audio transmitter, and battery pack. The interface also includes a helmet equipped with a video display, microphone, and headphones.
PCT Publication No. WO 94/11855 to Kuenster et al. discloses a video display system that includes a heads-up display and portable electronic device for projecting an enlarged virtual image of video information depicted on a video display wherein the virtual image is viewable by a user wearing the head-up display unit. The portable device includes a receiver for receiving radio-frequency-modulated video and audio signals and is coupled to the video display unit. Additionally, the portable device may be mounted on the frame of the heads-up display unit.
U.S. Pat. No. 5,717,414 to Bergsneider et al. discloses a video image tracking system for determining the position and orientation of an operator with respect to a simulator display. The system further includes a device for locating the detectable object within the simulator display and communicates this location to a VR system which displays the proper orientation and location of the virtual environment with respect to the operator.
Other references generally illustrative of the art of head-mounted displays used in virtual reality systems and related communications systems include U.S. Pat. No. 4,649,504 to Krouglicof, U.S. Pat. No. 4,866,229 to Scharfenberg, U.S. Pat. No. 5,406,415 to Kelly, U.S. Pat. No. 5,485,172 to Sawachicka et al., U.S. Pat. No. 5,671,158 to Fournier, et al., U.S. Pat. No. 5,742,263 to Wang et al., U.S. Pat. No. 5,757,339 to Williams et al., and U.S. Pat. No. 5,767,524 to Barbier et al.
Systems such as those described above for providing audio and visual cues to a user are subject to various limitations, including poor or non-existent support for multiple users, the possibility that a signal transmitted to a user will be improperly intercepted, low bandwidth of the transmission path between the processor and the user, high cost, restrictions on a user""s movement, and susceptibility to interference.
It is therefore an object of the invention to provide an improved system for providing visual and audio cues to a user.
It is a further object of the invention to provide a system for transmitting visual and audio cues in a wireless manner to a mobile user with improved bandwidth in the transmission path between the virtual reality processor and the user.
It is a further object of the invention to provide a system which wirelessly tracks a user""s location, head orientation, and/or orientation of appendages or attached objects.
It is a further object of the invention to provide a system for providing visual and audio cues to a user which is less susceptible to interference or interception of the signal between the processor and the user.
It is a further object of the invention to provide a system for providing visual and audio cues to a user which is less costly to manufacture.
It is a further object of the invention to provide a system for providing visual and audio cues to a user which provides fewer restrictions on user movement.
In a preferred embodiment, the invention provides a wireless transmission system for transmitting data to a user in a simulation system, the transmission system including a light source for generating a modulated light beam for transmitting the data, an active pointing mechanism for actively pointing the light source, an optical receiver carried by the user for receiving and demodulating the modulated light beam, and a display or audio source for using the data to provide stimuli to the user. The light source preferably includes a laser device which is intensity-modulated with a wave form appropriate for the audio and video interfaces being used. The active pointing mechanism preferably includes a two-dimensional gimbal which receives tracking information from a tracking detector that tracks the optical receiver, and which uses that tracking information to actively point the light source. A virtual reality processor processes position and orientation data and outputs video data and audio data for wireless transmission to the user""s head-mounted display and audio headset.